Chemical modification of cellulose by in situ reactive extrusion in ionic liquid

In order to prepare the spinning solution of cellulose with high concentration in environmentally friendly solvent, cellulose was chemically modified by in situ reactive extrusion with several chemicals, such as urea, phthalic anhydride (PA), maleic anhydride (MA) and butyl glycidyl ether (BGE) and with ionic liquid namely 1-N-butyl-3-methylimidazolium chloride (BMIMCl) as reaction medium. These four modifiers all in situ grafted onto cellulose and the modification effectiveness was found to decrease in the sequence, MA > PA > BGE > urea. The formation of side chain on cellulose backbone destroyed the regularity of cellulose chains and the hydrogen bond network efficiently. The concentration of modified cellulose in spinning solution can be up to 14-25%, comparing with 9% for unmodified cellulose in BMIMCl. The high solid content results in high efficiency and less energy consumption of fiber production and solvent recycle.